[rmc]

You do not have to distribute the source code of a GPL application with the binary. You merely have to make it available. For example, I have an Ubuntu Linux install CD with lots of GPL binaries and no source. It's perfectly legal for that binary-only CD to be distributed.

AFAIR from the VLC case, software distributed on the AppStore has extra restrictions on the user (You can only use it for personal reasons, you can only install (use?) it on 5 (or so) machines, etc.) GPL software cannot be distributed under these extra clauses.

If you are the sole programmer & copyright holder, then you are free to relicence/release your work under some other licence that is OK with these.

However if you are incorporating other GPL software (like in the VLC case) then you do not hold the copyright on that software, so the person who does have copyright on it is letting you distribute the software so long as you agree to certain terms. You cannot distribute someone else's GPL software on the Apple App Store because you would not be meeting the GPL requirements of "do not place any other restrictions on the software".

I delibrately phrased it as "Apple doesn't allow GPL" because this is not a technical problem, but a legal/contractual/business problem. Apple could choose to allow GPL. They do not. Microsoft, who called the GPL cancer, allow GPL Apps on Windows.

[Argorak]

Okay, thanks for the detailed explanation and the reasoning behind that sentence. Yes, Apple did not take any special action to support GPL in the app store.

Personally, I find it surprising that Apple, which leveraged open source to a huge effect and took stewardship of some high-profile OS projects (webkit, llvm/clang, CUPS), but allows other companies to position themselves as "open source friendly" alternatives. Especially as one of those companies is Microsoft.

[rmc]

Apple did not take any special action to support GPL in the app store.

You do not need to take any special action with any operating system to get it to support the GPL. What Apple have done is done special action (lots of EULA/contracts/etc.) that explicitly disallow the GPL.

The reason (I think) Apple are explicitly disallowing the GPL is because it would be incompatible with the DRM type systems that Apple use. It's more a case of 'If Apple distribute GPL software on their App Store, they might have to give away the DRM keys and allow anyone to run any programme on their iPhone'. That situation is something Apple don't want.

GPL programmes are still allowed on OSX obviously, and I think some of Microsoft's mobile and/or app store thingie explicitly ban GPL as well.

[Argorak]

Yes, you do (sometimes) have to take special action to support the GPL. For example, Ruby recently changed its license to allow the bundling of readline 6 with MRI. This was a distribution problem as well.

Show me the places where Apple EULA "explicitly" disallows the GPL (and not just includes things that are incompatible with the GPL). There certainly is GPLed Software in the app store, even with a notice included (see Battle of Wesnoth). If it was explicitly forbidden, that would not happen.

My interpretation is that Apple just doesn't care. The want Apple-signed code on their devices and if your license doesn't allow signed code, they won't help you. This by itself is sad and I would very much hope for that to be different, but not "explicitly disallowing".

[rmc]

I think MS were the ones that explicitly mentioned the GPL.

Apple do not explicitly mention it, however they have chosen to add extra restrictions to their licence, which goes above and beyond a normal "Download software from this web host". Explicit clauses that make the GPL incompatible are the same as "explicitly banning GPL apps".

The GPL is a massively popular licence, I believe Apple would have considered it. They appear to have rejected it.

[rmc]

You merely have to make it available.

Also, you don't have to make it available forever, I think the GPL says you only have to do it for 3 years. So you don't have to worry about someone in 50 years demanding some source code.